Added colon for GLOBAL OPTIONS and ENVIRONMENT VARIABLES in help heading

Before Fix: There were no colon(:) for GLOBAL OPTIONS and ENVIRONMENT VARIABLES
After Fix:There is a colon(:) for GLOBAL OPTIONS: and ENVIRONMENT VARIABLES:

http://rnd-github.huawei.com/paas/cli/issues/24
eof character is introduced. we should not introduce such formatting changes in commits. consider to preserve the original file contents. also look for the same in other files in this commit.